The present invention is directed to a nail. More particularly, the present invention pertains to a radially offset, full or partially round headed nail and a method of making same.
Nails are often used in power driving tools to quickly and efficiently secure objects such as wood. Generally, nails have a head and an elongated shank and are linearly collated in an adhesive strip made of plastic or paper tape or the like, with the shanks oriented in a parallel relationship. The nails are ejected sequentially as the driver blade of the power driving tool strikes each of the heads individually. The nails in the strip are, therefore, spaced apart so that the heads do not interfere with each other during discharge. As a result, because of the size and configuration of full-round heads, only a limited number of full-round head nails may be included in a particular strip.
To increase the number of nails per length of strip, manufacturers have developed offset nails in which the longitudinal axis of the shank is positioned radially off-center of the head. An offset head generally has a toe and a heel. The toe refers to the greater portion of the offset head, in the direction opposite to the radial displacement of the shank. The heel refers to the lesser portion of the head, in the direction of radial displacement of the shank from the center of the head. Portions of the heel and toe are unsupported by the shank of the nail.
Offset nails allow the pitch, i.e., the distance between the shanks of nails, to be closer together, allowing additional offset nails to be included per length of strip than traditional nails in a comparable strip. The power driving tool, therefore, needs to be reloaded less often, saving time. Often these offset nails are also redesigned with elongated or partially-rounded heads because partially-round head nails are easier to form than full-round head nails. Offset full-round head nails, however, are readily identified with concentric round head nails where construction codes define requirements for nail heads in specific fastening applications. The round head nails have a full 360 degree rim (as opposed to a 180 degree or other shaped configuration of head) giving extra clamping or, “hold down” so to speak, when the nail is driven into a nailing medium.
Regardless of whether the nail has a full-round head or a partially-round head, however, each is subject to similar deformations when driven. Due to the configuration of the nails in the collated strip, the offset nail can be struck at a position not supported by the shank, for example, at the toe. The force of the driving blade can bend the toe of the head if the head is not supported properly or if the head is too thin. In addition, the shank may also bend if the load from the force of the driving blade strike is not distributed through the axis of the shank properly. Furthermore, the junction between the head and the shank, the chamfer, may not be strongly attached, thus lead to breakage during nailing and causing the power driving tool to jam or fail.
To compensate for these challenges, offset full or partially round head nails have been manufactured with thickened heads. In addition, these nails have been manufactured such that the shank is slightly off-center to take advantage of the ability to combine more nails in a strip, but are not fully off-center of the head, leaving a heel about twenty (20) mils, so that less of a toe is present. However, these solutions require additional material to be used to make the head thicker, and the number of nails per strip is not maximized because of the size of the heel under the head.
Accordingly, there is a need for an offset head with a full or partially-round head that can be collated to maximize the number of nails in a strip. In addition, it would be desirable for such a nail to withstand large forces without bending or yielding without adding material.